When enduring 6 months of calorie restriction to lose weight, a study found that if participants ate around 28 more grams of protein per day, the food choices they made changed for the better.
Better was defined as less sugar and grains, and more green vegetables.
The study is modern in that it starts with two preconceptions that are valuable and important for context. The first is that diets for weight loss that focus on the restriction of calorie consumption have also been shown to quite often reduce healthy food and micronutrient intake, while the second is that weight loss of just 5% is enough to lower the risk of chronic disease like cardiovascular disease.
The USDA, places the recommended protein intake, as WaL has reported, at 0.8 grams of protein for every kilogram of body weight after trying to figure out the minimum amount needed to prevent soldiers in World War II from getting sick.
The study looked at a slightly higher amount of 1 gram per kilo and compared it with the USDA recommendation, finding higher weight loss in the higher protein group, and better food choices.
“An increased protein intake of 1.0 g/kg is not especially high, and adherence to this should be achievable with nutrition counseling, even in individuals who typically consume low protein intakes,” the authors note. Indeed even the USDA recommends as much as 1.8 grams per kilogram of body weight for those below such as athletes or nursing women.
Interestingly, along with losing more fat mass and maintaining more lean body mass after a six-month weight loss diet, the study found that food choices tended to improve, going from unhealthy sugars to green vegetables.
It’s about feeling full
A sensitivity analysis found that the higher protein intake group, of around 79 grams per day or 20% of overall calorie intake, increased their scores significantly on the Healthy Eating Index.
This score was tallied by greater consumption of green vegetables, and less consumption of sugars and refined grains, and the protein was almost all animal sources including poultry, unprocessed red meat, seafood, cured meat, cheese, milk, eggs, and nuts/seeds.
Micronutrients of calcium, magnesium, potassium, and choline, were below recommended levels in both sets of the dieters which could be resulting from poultry making up most of the protein intake. More red meat could have alleviated the mineral and choline loss, the latter of which is almost only found richly in red meat and eggs.
But why the healthy eating scores were different could come down to the fact that protein is more satiating, and can stave off low energy-driven cravings for processed or sugary foods.
Along with keeping us fuller for longer, it also has a stabilizing effect on blood sugar, preventing it from lowering between meal times.
A problem with presenting findings like these to the public, the authors write, is that a variety of potentially-harmful nutrients tend to accompany higher protein intakes in American diets. A profile of higher saturated fat, cholesterol, sodium, and added sugar with less fiber, is not somehow brought about by eating meat, but this tends to, in America, accompany higher protein consumption in the literature.
“Most measures of protein quality by amino acid composition and digestibility (protein digestibility-corrected amino acid score and digestible indispensable amino acid score) suggest that proteins from animal sources are more complete to varying degrees than plant sources,” the authors note.
“Multiple other studies have shown that individuals consuming plant-based diets meet protein needs and have a higher quality diet than omnivores, but this tends to be driven by fruit and vegetable intake, not necessarily higher quality protein intake”. WaL